Panicum virgatum ‘Thundercloud’, hereinafter also referred to as ‘Thundercloud’ and “the plant” is a new and distinct cultivar of Switch Grass. It was a cross by Gary M. Trucks in 2002 between Panicum ‘Cloud Nine’ (not patented)×Panicum virgatum ‘Northwind’ (not patented) at a nursery in Benton Harbor, Mich. and selected for further observation in 2003. The plant has been successfully asexually propagated by division at the same perennial plant nursery in Benton Harbor, Mich. and found to produce identical plants that maintain the unique characteristics of the original plant. The plant is stable and reproduces true to type in successive generations of asexual reproduction.